Historical clue formulations

• Head toward the setting sun — 2013-11-05
• Follow the sun? — 2013-09-14
• Advice heeded by a pioneer — 2012-06-28
• Film in which the Marx Brothers join the gold rush — 2011-10-07
• 1940 Marx Brothers movie — 2006-01-25
• Advice of 1851 — 1998-04-17